Chemoprevention of DMBA-induced UV-B promoted, NOR-1-induced TPA promoted skin carcinogenesis, and DEN-induced phenobarbital promoted liver tumors in mice by extract of beetroot.
ABSTRACT Our previous studies identified the extract of Beta vulgaris (beetroot), commercially also known as betanin, as a potent cancer chemopreventive agent in both in vitro Epstein-Barr early antigen activation assay and in an in vivo two-stage mouse lung and skin carcinogenesis. To explore this issue further, we have now investigated its cancer chemopreventive potentials in three different chemical carcinogen initiation-promotion experimental tumor models in mice. Following tumor initiation with 390 nmol of 7,12-dimethylbenz(a)anthracene (DMBA) in 100 microl of acetone, the mouse skin tumor promotion with 3430 J/m(2) of ultraviolet light-B (UV-B) as well as splenomegaly was significantly inhibited by oral administration of 0.0025% betanin. At the same dose, betanin also afforded significant protection in the mouse skin cancer model following the topical application of 390 nmol of (+/-)-(E)-4-methyl-2-[(E)-hydroxyamino]-5-nitro-6-methoxy-3-hexanamide (NOR-1) in 100 microl of acetone and promoted by topical administration of 1.7 nmol of 12-O-tetradecanoylphorbol-13-acetate (TPA). In the two-stage model of hepatocarcinogenesis in mice with N-nitrosodiethylamine (DEN, 30 mg/kg) as the initiator and phenobarbital as the promoter, oral administration of 0.0025% betanin also showed a very significant inhibition of both the incidence and multiplicity of the liver tumors. These findings along with our initial reports suggest that betanin which is a regularly consumed natural product colorant is an effective cancer chemopreventive agent in mice. The most interesting observation is that the cancer chemopreventive effect was exhibited at a very low dose used in the study and thus indicating that beetroot warrants more attention for possible human applications in the control of malignancy.
SourceAvailable from: Gerald Rimbach[Show abstract] [Hide abstract]
ABSTRACT: Betanin is a red pigment present in beet root. Recently, potential health benefits of betanin-rich beet root have been suggested. However, little is known regarding the free radical scavenging and antioxidant activity of betanin. Electron spin resonance spectroscopy (ESR) and spin trapping techniques were applied to evaluate the ability of betanin to scavenge hydroxyl, superoxide, 2,2diphenyl-1-picrylhydrazyl (DPPH), and galvinoxyl free radicals. In addition, we tested in cultured cells the ability of betanin to prevent DNA damage and to induce the transcription factor Nrf2 (nuclear factor (erythroid-derived 2)-like 2) as well as its down-stream target heme oxygenase1 (HO-1), paraoxonase1 (PON1) and glutathione (GSH). Betanin dose-dependently scavenged DPPH-, galvinoxyl-, superoxide-, and hydroxyl-radicals in the ESR and spin trapping studies and prevented hydrogen peroxide induced DNA damage as determined by the Comet assay. Furthermore, betanin treatment induced the transcription factor Nrf2 and resulted in an increase of HO-1 protein levels, PON1-transactivation and cellular GSH. Present data suggest that betanin is both a free radical scavenger and an inducer of antioxidant defense mechanism in cultured cells.Food and Chemical Toxicology 08/2014; 73. DOI:10.1016/j.fct.2014.08.007 · 2.61 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Metabolite profiling of red and white pitayas (Hylocereus polyrhizus and Hylocereus undatus) was performed using gas chromatography-time-of-flight-mass spectrometry and ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry with multivariate analysis. Different species and parts of pitayas (red peel, RP; white peel, WP; red flesh, RF; and white flesh, WF) were clearly separated by partial least-squares discriminate analysis. Furthermore, betalain-related metabolites such as betacyanins and betaxanthins or their precursors were described based on their metabolites. The results of antioxidant activity tests (DPPH, ABTS, and FRAP), total phenolic contents (TPC), total flavonoid contents (TFC), and total betacyanin contents (TBC) showed the following: RP ≥ WP > RF > WF. TPC, TFC, TBC, and betalain-related metabolites, were higher in the peel than in the flesh, suggested to be the main contributors to antioxidant activity in pitayas. Therefore, peels as well as pulp of pitaya could help beneficial in food industry.Journal of Agricultural and Food Chemistry 08/2014; 62(34). DOI:10.1021/jf5020704 · 3.11 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Abstract Betalains are a family of natural pigments present in most plants of the order Caryophyllales. They provide colors ranging from yellow to violet to structures that in other plants are colored by anthocyanins. These include edible fruits and roots but also flowers, stems, and bracts. The recent characterization of different bioactivities in experiments with betalain-containing extracts and purified pigments has renewed the interest of the research community in these molecules used by the food industry as natural colorants. Studies with multiple cancer cell lines have demonstrated a high chemopreventive potential that finds in vitro support in a strong antiradical and antioxidant activity. Experiments in vivo with model animals and bioavailability studies reinforce the possible role played by betalains in the diet. This work provides a critical review of all the claimed biological activities of betalains, showing that the bioactivities described might be supported by the high antiradical capacity of their structural unit, betalamic acid. Although more investigations with purified compounds are needed, the current evidences suggest a strong health-promoting potential.Critical Reviews in Food Science and Nutrition 08/2014; DOI:10.1080/10408398.2012.740103 · 5.55 Impact Factor